However, sources have briefed Sky News political editor Andrew Clennell and The Australian columnist Peter van Onselen that the vote was 11-10, even though it was a secret ballot so it's unclear how credible that number is.

If the result was that close, commentators believe Mr Barnaby will definitely challenge again. Van Onselen tweeted that one Nationals MP said Mr McCormack "won't survive the week".

Mr McCormack also congratulated David Littleproud on being elected the new deputy leader, to replace Bridget McKenzie.

Acting Prime Minister Michael McCormack with Member for Maranoa David Littleproud.Matthew Purcell

"We will continue as a united team to put the people of regional Australia first and foremost.

I want to thank my colleagues for again placing their faith in me.

"I think now we need to draw a line in the sand and focus on the fire victims.

"There've been many who lost their businesses, lost their homes, lost their farms."

Matt Canavan resigned from the ministry on Monday evening to endorse Mr Joyce.

"We need a bulldog, we need a fighter," he told reporters in Canberra.

The Nationals party room will meet in Canberra today where federal backbench MP Llew O'Brien will call for a leadership spill, opening up Mr McCormack's job.

Mr O'Brien's spill motion will need to be seconded to trigger a vote on Mr McCormack's leadership.

The party must also choose a new deputy leader to replace dumped minister Bridget McKenzie, with Queensland frontbencher David Littleproud the favourite.

BARNABY GRILLED AS SPILL LOOMS

Barnaby Joyce has been grilled as he aims to get his old job as Deputy Prime Minister back.

The Nationals partyroom will meet in Canberra where federal backbench MP Llew O'Brien will call for a leadership spill, opening up Michael McCormack's job.

Mr Joyce, the party's former leader, told Mr McCormack on Monday afternoon he would have a tilt at the role.

Speaking on Today this morning, Mr Joyce said it was time for a change.

"We are two years out from the next election. We have had two years with Michael. We respect the job Michael has done but if there is a time to consider where we are going and how we get there, then it is today," he said.

But Mr Joyce was grilled by Today host Allison Langdon about what he had learnt since moving to the backbench.

"You said you have spent the past two years reflecting on your faults. What are they and what have you learnt?" Langdon asked.

"Of course, I have got to make sure that we have a strong team. It is not about Barnaby. It is about the team. It is about making sure..."

But Langdon cut Joyce off, asking again: "No, no, but you talked about yourself personally reflect ongoing your faults. I'm asking you what are those faults and what have you learnt?"

Mr Joyce said sometimes he was too "enthusiastic".

Allison Langdon asked what happens if Barnaby loses the plot again.

"I'm enthusiastic and sometimes enthusiastic comes too enthusiastic and leaves people behind. You have to take down a cog. You have to make sure first and foremost you are listening to other people and hearing what their concerns are," he replied.

"Look, I have paid a heavy price and I have had two years to reflect on that and I'm not going to waste those two years. I'm going take that reflection and try and make myself a better man, which we all do.

"We all make mistakes and I think Australia is the place where, if you make a mistake, they will back you in again as long as you show that you have basically taken your medicine."

Langdon then asked: "Barnaby, the problem is your colleagues now need make a decision. A huge call. What they have got right now is useless. But are you worth taking a huge risk for. What if you lose the plot again?"

But Mr Joyce said he had a "very good structure" around him now.

"Of course (partner) Vikki (Campion) is down here with the boys as we speak. I also lean on people around me to make sure that I have got that support structure and I have got good friends who clearly understand that you have got to temper enthusiasm with the capacity to

keep people on board in your business dealings and in your personal life."

Barnaby Joyce.

LIBERALS WILL WORK WITH NEW LEADER

Federal Environment Minister and Liberal MP Sussan Ley said the party would be able to work with whoever their coalition party appoints.

"This has nothing to do with the Liberal party," Ms Ley told Nine on Tuesday.

"We're ready to work with whoever's successful.

"We will continue to work together as a government."

Mr Joyce has the support of backbencher Matt Canavan, who resigned from the ministry on Monday evening.

"We need a bulldog, we need a fighter," he told reporters in Canberra. "I think Barnaby has proven himself as a stayer."

The Queenslander wouldn't say if he thinks Mr Joyce has the numbers to win.

"I have not lobbied other members ... I have no idea about the overall make up of the result tomorrow."

Mr McCormack had earlier dismissed speculation his job was at risk and was confident he would continue as leader.

Nationals chief whip Damian Drum said Tuesday's spill motion would need to be seconded to trigger a vote on Mr McCormack's leadership.

"Barnaby would realise that, in my opinion, he doesn't have the numbers," he told the ABC.

"There's not much point in challenging if you don't have the numbers."

But Mr Drum admitted Mr Joyce had made no secret of his ambitions to return to the leadership.

"At the moment, Michael is the leader. Michael is doing a ripping job and he has fantastic support within the room," the Victorian MP said.

Nationals frontbencher Darren Chester, who is in line for a return to cabinet, also threw his support behind Mr McCormack.

The party must also choose a new deputy leader to replace Bridget McKenzie. Queensland frontbencher David Littleproud is the frontrunner. NSW backbencher David Gillespie is the only confirmed candidate but has struggled to get the support of colleagues in the past.

Mr Littleproud, who has the water, drought and emergency management portfolios, is the Nationals' most senior cabinet minister aside from Mr McCormack.